Our lab has had some problems using the Eppendorf microneedles for
Drosophila embryos. They had become too flimsy and would not penetrate
the chorion without breaking. We have just found that needles pulled
for C. elegans injection (thanks to the Saxton and Strome labs for
working out the conditions) work really well for Drosophila: here is the
information.
Using a Sutter Instruments Model P-87 Flaming/Brown Micropipette puller,
set the program as follows: Heat=600, Pull=40, Vel=25, Time=100. The
pressure should be toggled to 600.
The glass used is from World Precision Instruments: Kwik-Fil
Borosilicate Glass Capillaries, Item No. 1B100F-6; this glass has a
microfilament in the capillary tube.
We continue to use the eppendorf microloaders for loading the DNA into
the needles.
Stacy Holtzman
Kaufman Lab, Indiana University